The northern parts of the hotspot in Ecuador and the Colombian Chocó are characterized by extremely wet or pluvial forests that receive eight meters of annual rainfall and have a diversity per hectare of as many as 300 tree species.

Overall, a warmer climate is very likely to lead to a shift toward a more pluvial runoff regime as a greater proportion of the annual precipitation falls as rain rather than snow; the magnitude of the peak of spring snowmelt declines; thawing permafrost increases near-surface storage and reduces runoff peaks; and a more active groundwater system augments base flows.

They demonstrated that most rivers are very sensitive to temperature rises on the order of 1 to 3 ºC, and that nival (snow-dominated) rivers become less stable while pluvial (rain-dominated) rivers become more stable.

The Mojave Playas are generally smaller in area than the Lahontan and Tonopah Playas (13h) and are not part of the broad Pleistocene pluvial basins that are found in the Central Basin and Range (13) to the north.

A probable shift to a more pluvial system with smaller and less intense freshet and ice breakup is very likely to decrease the frequency and magnitude of natural disturbances, and reduce the ability of flow systems to replenish riparian ecosystems, particularly river deltas.